We can place F# as the key signature for G major before the scale: Notice that there is only one scale that has one sharp - the G major scale. Refer back to the scales you wrote at the end of the previous unit. There’s a reason why those sharps are written in the special order shown above, and we’ll investigate that now. A group of sharps or flats applied globally at the beginning of a line of music is called a KEY SIGNATURE. That group of sharps between the clef and the meter sign tells readers that every F, C, G, D, A, and E (regardless of octave) is to be raised by a half step. We can place all of the sharps or flats from the key in a cluster at the beginning of each line, like this: It is much more efficient to indicate this once at the beginning of each line of music, rather than to write a sharp before every note that needs one. We know just which notes will always be raised by a sharp in the key of F# major: F#, G#, A#, C#, D#, and E#. So let’s refer back to the F#-major scale: That works, but it’s cumbersome and unnecessarily repetitive. Look back to the scales you wrote at the end of the last unit, and consider using the notes of the F# major scale to notate “Frère Jacques” by writing a sharp before every note that needs one: The Simplicity and Convenience of Key Signatures This unit shows you a more convenient way of altering pitches globally and systematically, through the system of key signatures. But writing sharps or flats before every note of a piece of music becomes tedious and unnecessary. Through them, you developed skills in constructing whole and half steps, became more familiar with the sharp and flat symbols, and gained a more intimate knowledge of the structure of the major scale. The scales you wrote at the end of the last unit served several purposes.

Music keys with 3 sharps